The present application claims the priority of JP 2000-365696, filed in Japan on Nov. 30, 2000, the entire contents of which are hereby incorporated herein by reference.
The present invention relates to a magnetic multi-layer film manufacturing apparatus.
In the description of the background of the present invention that follows reference is made to certain structures and methods, however, such references should not necessarily be construed as an admission that these structures and methods qualify as prior art under the applicable statutory provisions. Applicants reserve the right to demonstrate that any of the referenced subject matter does not constitute prior art with regard to the present invention.
Magnetoresistive effect-type magnetic heads, which constitute playback magnetic heads in which a magnetoresistive effect element is employed as a magnet-sensitive element, have actual application as playback parts for hard disk drives and the like. TMR elements have begun to be employed in recent years as magnetoresistive effect elements used in magnetoresistive effect-type magnetic heads. TMR elements are elements that use a TMR (Tunneling Magnetoresistive) effect. The TMR effect is a magnetoresistive effect produced by tunnel junctions in which an insulating body is enclosed by a strong magnetic body. Compared to elements of the prior art that use an AMR (Anisotropic Magnetoresistive) effect and GMR (Giant Magnetoresistive) effect, TMR elements are advantageous in that they have a large MR ratio. The MR ratio thereof is 30 to 50%.
The films from which the above-described TMR elements are configured comprise, specifically, a multi-layer film structure in which a first soft magnetic layer, an insulating layer, a second soft magnetic layer, and an antiferromagnetic layer are deposited successively. In these TMR elements, film deposition is performed by the use of individual sputtering of the respective plurality of magnetic films, and the film formation of the insulating layer is performed using a metal oxide reaction.
As is described above, the conventional magnetic multi-layer film manufacturing apparatus, in which film layers of the multi-layer film are successively deposited on a substrate, performs continuous multi-layer film deposition. FIG. 6 shows a hitherto used representative sputtering film forming apparatus for heads. In this sputtering film depositing apparatus, a comparatively large single film-depositing chamber 103 is provided in the perimeter of a transferring chamber 102 which includes a robotic-transferring device 101. Targets 104A to 104J for the separate sputtering deposition of the various magnetic layers from which the magnetic layer films are configured, are provided in a circular arrangement in the inner part of the film-deposition chamber 103. A substrate carried in from a loading chamber 105 is introduced to the film-deposition chamber 103 by the robot carrying device 101 within the carrying chamber 102, whereupon the formation of the magnetic film layer on the substrate is performed. The manufacture of the magnetic multi-layer film is performed by sputtering film deposition in which the substrate is caused to move, by way of example, in a clockwise direction, and is stopped, by the movement thereof, below each of the targets 104A to 104J. The magnetic multi-layer film is manufactured on the substrate using the single film-deposition chamber 103, in accordance with targets arranged in an order established in advance, by the continuous successive film deposition of all of the magnetic film layers from a bottom layer in accordance with a set order. In this sputtering film deposition, normally, the targets are arranged horizontally, and the surface of the substrate is arranged in an opposing state with respect to the surface of said targets. When the continuous multi-layer film depositing of the magnetic multi-layer filmsxe2x80x94which use the plurality of targets 104A to 104J correspondent to the number of layers of multi-layer magnetic films in the film-depositing chamber 103xe2x80x94is completed, the substrate in which the film-depositing process has been completed is carried along by the robot transferring device 101 of the transferring chamber 102, and is carried out through an unloading chamber 106.
In the above-described conventional continuous multi-layer film deposition of the magnetic multi-layer film, because of the configuration of the sputtering film depositing apparatus, deposition is performed, without interruption of the film deposition, from the bottommost layer until completion of the film deposition of the uppermost layer. On the other hand, the configuration for the production of multi-layer films from which semiconductor devices are made is generally one which comprises a transferring chamber at the center and a plurality of film-depositing chambers provided in the perimeter thereof and, as a cluster-type, is one in which each of the multi-layer films are deposited using a plurality of film-depositing chambers. Compared to the configuration of the multi-layer film manufacturing apparatus pertaining to ordinary semiconductor devices, the configuration of a representative multi-layer sputtering film depositing apparatus of the prior art may be described as unique.
In the development of a sputtering film depositing apparatus for magnetic heads that is suitable for the mass production of magnetic heads for the abovementioned TMR elements that comprise magnetic multi-layer films, the adoption of a configuration that is compatible with the general configuration of a semiconductor device manufacturing apparatus, and not a unique configuration, is demanded.
In addition, there will be increased demand in the future for, as a non-volatile semiconductor memory, an MRAM (Magnetoresistive Random Access Memory) that comprises a magnetic multi-layer structure similar to TMR elements in terms of improvement to memory integration degree and high-speed rewriting performance. In cases where, in response to this demand, the manufacture of magnetic multi-layer films has been performed by manufacturers which ordinarily produce semiconductor devices using the conventional configuration of the apparatus in which the multi-layer film deposition is performed continuously using one large film-depositing chamber, a sense of incompatibility has been felt in comparison to normal semiconductor device manufacturing methods. Thereupon, the semiconductor manufacturers, in consideration of the manufacture of MRAM using their own semiconductor production lines, have come to demand a magnetic multi-layer film manufacturing apparatus comprising a configuration (cluster system) suitable for semiconductor production lines.
In addition, in the continuous film deposition of conventional magnetic multi-layer films, because the film deposition must be continuous, without interruption, from the bottommost layer of the substrate to the uppermost layer, and a large number of magnetic films are deposited in one action, concerns exist regarding the restricting of improvements to the MR ratio.
Furthermore, in the production of MRAM, greater productivity is demanded compared to the production of magnetic heads. Based on the representative configuration of the magnetic multi-layer film manufacturing apparatus of the prior art described above, it is difficult to expect productivity improvements because of the continuous multi-layer film deposition.
An objective of the present invention, which is designed with the above-noted problems in mind, lies in the provision of a magnetic multi-layer film manufacturing apparatus which, in the production of MRAM and magnetic heads comprising TMR elements and so on, comprises a normal configuration which, notably, is a configuration suitable for the deposition of magnetic multi-layer films by manufacturers of semiconductor devices, and in which, furthermore, the film performance can be increased and productivity can be improved.
A magnetic multi-layer film manufacturing apparatus comprises a transferring chamber, a plurality of film-depositing chambers in operative communication with the transferring chamber, each film-depositing chamber comprising a rotatable substrate holder, a plurality of targets, and a double layer rotating shutter mechanism disposed between the rotatable substrate holder and the plurality of targets, each film-depositing chamber controllable to deposit at least one layer of a magnetic multi-layer film structure, and a robotic transferring device disposed in the transferring chamber, the robotic transferring device rotatable about a central location and freely stretchable.
A deposition apparatus comprises a chamber comprising at least one housing for a target on a first surface and a shutter mechanism, the shutter mechanism comprising a first platen having at least two openings therein aligned radially, and a second platen having one opening therein. The first platen and second platen are arranged substantially coaxial and are each freely and independently rotatable about an axis within the chamber such that one of the at least two openings in the first platen and the one opening in the second platen are substantially longitudinally aligned with respect to a center axis of the at least one housing for a target.
A method of forming a magnetic multi-layer film positions a substrate into a first film deposition chamber from a carrying chamber in operational communication therewith, deposits a first magnetic film group, the first magnetic film group comprising a first plurality of magnetic layers, each magnetic layer deposited successively on the substrate continuously in a laminated state to form a magnetic multi-layer film, positions the magnetic multi-layer film into at least a second film deposition chamber from the carrying chamber in operational communication therewith, and deposits at least a second magnetic film group, the at least second magnetic film group comprising a second plurality of magnetic layers, each magnetic layer deposited successively on the magnetic multi-layer film continuously in a laminated state to form a stacked magnetic multi-layer film.
Another method of forming a magnetic multi-layer film introduces a substrate into a carrying chamber having a plurality of deposition chambers in operational communication therewith and a manipulating device, operates the manipulating device to place the substrate in a cleaning chamber, cleans the substrate by an etching or a sputtering technique, operates the manipulating device to successively place the substrate in each of the plurality of deposition chambers in a predetermined sequence, and deposits a plurality of magnetic film groups to form a magnetic multi-layer film, the plurality of magnetic film groups comprising a plurality of magnetic film layers, each one of the plurality of magnetic film groups continuously deposited in a laminated state in an associated one of the plurality of deposition chambers.
A further method of depositing material from a plurality of targets in a chamber rotates a first platen having one opening to align the one opening with a first of a plurality of targets, rotates a second platen having at least two openings therein aligned radially to align a first of the two openings with other than a first of the plurality of targets, sputters the first of the plurality of targets for a predetermined time, rotates the second platen to align the first of the two openings with the first target, and deposits material from the first of the plurality of targets onto a substrate.
In a first aspect, which constitutes a magnetic multi-layer film manufactured by the successive deposition on a substrate, in a laminated state, of multi-layer films comprising a plurality of magnetic films, a plurality of magnetic films are divided into a plurality of groups and each of the plurality of groups comprises a plurality of magnetic films deposited continuously in a laminated state. The plurality of magnetic films contained in the plurality of groups are configured so as to be successively deposited on the substrate using the same film-depositing chamber.
Based on the above-described magnetic multi-layer film manufacturing apparatus, sputtering film deposition can be performed by the division of a multi-layer magnetic film into a plurality of groups in accordance with a specific reference criterion and, as a result, a magnetic multi-layer film manufacturing apparatus configuration comprising a large number of film-depositing chambers is attained. The attainment of a cluster system in the manufacture of a magnetic multi-layer film is concurrent with the methods used by manufacturers of semiconductors.
In a second aspect, it is preferable that the above-described configuration be provided with a single film-depositing chamber correspondent to each of the plurality of groups, and that it comprises a plurality of film-depositing chambers, the number of which is correspondent to the number of the groups. In the deposition of magnetic multi-layer films which can be divided into a plurality of groups, it is preferable that film deposition processing be performed for each group, wherein the plurality of magnetic films belonging to the groups are continuously deposited by the sputtering of a shared film-depositing chamber.
In a third aspect, it is preferable that, in the above-described configuration, the configuration comprises, in addition to the abovementioned plurality of film-depositing chambers for depositing the abovementioned magnetic films, a film-depositing chamber for the deposition of a film of another nature. Processing to form oxide films at stages along the way is necessary in magnetic multi-layer films, so a film-depositing chamber such as this is specially provided. As this is a cluster-type film manufacturing apparatus, another film-depositing chamber can be provided in the perimeter of the transferring chamber that is positioned in the center.
In a fourth aspect, it is preferable that, in the above-described configuration, the plurality of film-depositing chambers be configured in such a way as to be arranged in the perimeter of a transferring chamber positioned in the center which comprises a substrate transferring device. A cluster-system film manufacturing apparatus is attained, and this affords the merger with the semiconductor device methods.
In a fifth aspect, it is preferable that, in the above-described configuration, a plurality of targets correspondent to the plurality of magnetic films contained in the groups be arranged in the film-depositing chambers for depositing the plurality of magnetic films contained in the groups, and that the substrate be arranged in a rotating state in the center of the base surface of the film-depositing chamber, and that the plurality of targets be provided in an incline toward the substrate. For the deposition of a plurality of types of magnetic film by sputtering using a single film-depositing chamber, and for the efficient deposition of magnetic films of high performance, an oblique film-deposition configuration is preferred.
In a sixth aspect, it is preferable that, in the above-described configuration, a double-layer structure, comprising two shutter plates which rotate separately, be provided in the front surface of the abovementioned plurality of targets of the abovementioned film-deposition chamber. The cross-contamination between the targets provided on the same film-depositing chamber can be prevented by the provision of this double shutter structure.
In a seventh aspect, it is preferable that, for the formation of the plurality of groups in the above-described configuration, a group be formed by the division of a metal oxide layer and a magnetic layer continuous therewith contained in the above-described multi-layer films, and furthermore, an antiferromagnetic layer and a magnetic layer continuous therewith be taken as the same group and continuous film deposition be performed in the same chamber.